Mobile communication devices are in widespread use throughout the world, and especially in metropolitan regions of the world. These devices have evolved from simple devices that merely support wireless mobile telephony to multi-function, multi-mode devices that can communicate in a variety of frequency bands using a variety of air interface protocols, modulation schemes, and so on. Manufactures have worked to keep such device relatively inexpensive, as well as physically small with ever decreasing electrical power consumption rates.
The combination of making the device multi-modal and the desire to keep the device physically small has caused designers and manufactures to find ways of combining circuits and circuit elements such that they can be used for multiple modes, rather than having dedicated circuits and systems for each mode of communication. One of the components of mobile communication devices that occupy a substantial space is the antenna structure and supporting circuitry and mechanical features. Typical whip antennas do not perform well across multiple bands, and require a substantial amount of mechanical support. Using multiple antennas for different bands also increases the space occupied by antennas. Therefore there is a need for a compact, multi-band antenna structure that reduces the amount of space and mechanical features needed in the device.